The development of digital image technology has been accompanied by progress towards the realization of a video format called “4K” with a screen resolution of around 4,000 horizontal pixels and around 2,000 vertical pixels. In addition, research and development are also progressing into a video format that exceeds 4K and has a screen resolution of 7,680 horizontal pixels and 4,320 vertical pixels.
For video formats with such screen resolutions, images are displayed not on a single display but instead spread across a plurality of displays. When a digital image signal is transferred to a plurality of displays, a method is used where the transmitter of the images transfers image data of a line sequence and the individual displays detect and extract the regions to be displayed. Technologies for transferring and extracting images are disclosed in Patent Literature 1 and 2, for example.